J Radioanal Nucl Chem
`DOI 10.1007/s10967-017-5595-1
`
`Freeze-dried multi-dose kits for the fast preparation of
`177Lu-Tyr3-octreotide and 177Lu-PSMA(inhibitor)
`under GMP conditions
`
`Myrna Luna-Gutie´rrez1 • Tania Herna´ndez-Jime´nez1 • Luis Serrano-Espinoza1 •
`Alejandro Pen˜ a-Flores1 • Airam Soto-Abundiz1
`
`Received: 29 August 2017
`Ó Akade´miai Kiado´, Budapest, Hungary 2017
`
`177Lu-PSMA(in-
`Abstract 177Lu-Tyr3-octreotide
`and
`hibitor) radiopeptides were obtained with radiochemical
`purities of 98.7–100%, from lyophilized formulations after
`reconstitution with sterile solutions of 177LuCl3 (40 GBq/
`mL) without the need for further purification or steriliza-
`tion processes. More than 50 radiochemical syntheses were
`performed with a failure rate of 0% and radiochemical
`yields of 94–97%. From one lyophilized kit of DOTA-
`Tyr3-octreotide or DOTA-iPSMA, it was possible to obtain
`from 5 (7.4 GBq) to 10 (3.7 GBq) doses suitable for
`patients. Also, by using a sterile solution of 177LuCl3
`approved as a radiopharmaceutical precursor for human
`use, it is possible to obtain GMP-compliant 177Lu-peptides
`from sterile freeze-dried formulations without the need of
`using commercially-available radiochemical synthesizers.
`
`Keywords 177Lu 177Lu-labeled peptides 177Lu
`formulations PSMA inhibitor Tyr3–octreotide Freeze-
`
`dried kit
`
`Introduction
`
`Nowadays, 177Lu is widely used as a therapeutic radionu-
`clide for targeted radiotherapy because of its excellent
`nuclear properties (half-life of 6.647 d, b-max emission of
`0.497 MeV and c radiation of 0.208 MeV, useful for
`
`& Myrna Luna-Gutie´rrez
`myrna.luna@inin.gob.mx
`
`1 Department of Radioactive Materials, Instituto Nacional de
`Investigaciones Nucleares, Carretera Me´xico-Toluca S/N,
`52750 Ocoyoacac, Estado de Me´xico, Mexico
`
`diagnostic imaging), coordination to different chelator-
`biomolecules and commercial availability [1, 2].
`Of particular concern are the 177Lu-Tyr3-octreotide
`(177Lu-DOTA-Tyr3-octreotide; DOTA = 1,4,7,10-tetraaza-
`0
`00
`,N¢¢¢-tetraacetic acid) and 177Lu-
`cyclododecane-N,N
`,N
`iPSMA (iPSMA = prostate-specific membrane antigen
`inhibitor, e.g., DOTA-PSMA-617) radiopharmaceuticals,
`which have successfully been used in the treatment of patients
`with neuroendocrine tumors and advanced metastatic pros-
`tate cancer, respectively [3–5].
`Nevertheless, the current challenge in the routine pro-
`duction of 177Lu radiopharmaceuticals is the development
`of quick and efficient processes that comply with the
`requirements established by regulatory authorities regard-
`ing Good Manufacturing Practices (GMP). One approach is
`the use of commercially-available radiochemical synthe-
`sizers connected or adjacent to ISO Class 5 areas, from
`which the automated procedure allows to perform and
`record critical steps during the batch production such as the
`filter membrane integrity test, as well as to carry out the
`dosing process under clean air conditions. However, the
`radiochemical yield using synthesizers ranges from 74 to
`90%, and the number of therapeutic doses obtained by
`batch is usually limited to or less than three [6–8]. Fur-
`thermore, the acquisition of commercial disposable cas-
`settes and specific reagent kits for each produced batch is
`mandatory, significantly increasing production costs.
`It has also been previously reported that various lyo-
`philized formulations for
`the one-step preparation of
`177Lu-DOTA-Tyr3-octreotate (177Lu-DOTA-TATE) and
`177Lu-DOTA-Tyr3-octreotide (177Lu-DOTA-TOC), with
`results utilizing 177Lu prepared by neutron
`excellent
`irradiation of 176Lu (carrier added) or 176Yb (non-carrier
`added) [9–12]. Nonetheless, said formulations are repor-
`ted as kits for the preparation of mono-doses (up to
`
`123
`
`Evergeen Ex. 1025
`1 of 8
`
`

`

`7.4 GBq, one dose for one patient), which are reconsti-
`tuted with solutions of 177LuCl3 sterilized through a
`0.22 lm membrane, for which its certification as a GMP
`product authorized for use in humans, is not clear.
`The non-carrier added 177LuCl3, prepared as a sterilized
`solution with a content of bacterial endotoxin equal to or
`below 20 EU/mL and a radioactive concentration of
`40 GBq/mL (EndolucinBeta,
`ITG, Germany), was
`approved in 2016 by the European Medicines Agency
`(EMA) as a radiopharmaceutical precursor for human use.
`Since the specific activity and the radioactive concentration
`of 177LuCl3 are routinely reproducible, it is possible to
`design freeze-dried sterile formulations to obtain 177Lu-
`peptides by simple reconstitution of a lyophilized powder
`with the sterile solution of LuCl3, followed by heating of
`the vial for a complete 177Lu-conjugate formation under
`sterile conditions.
`The aim of this study was to develop freeze-dried, multi-
`dose formulations for the preparation of 177Lu-Tyr3-oc-
`treotide and 177Lu-iPSMA (up to 37 GBq/vial) in high
`radiochemical yields without the need for further purifi-
`cation or sterilization processes under GMP conditions.
`
`Experimental
`
`Design of the freeze-dried formulations
`
`Lutetium (177Lu) chloride was obtained from ITG, Ger-
`many (EndolucinBeta 40 GBq/mL, in aqueous 0.04 M HCl
`solution, [ 3 TBq/mg). DOTA-iPSMA (1,4,7,10-tetraaza-
`0
`00
`,N¢¢¢-tetraacetic acid -hydrazinoni-
`cyclododecane-N,N
`,N
`cotinyl-lysine-urea-glutamate derivative) and DOTA-Tyr3-
`octreotide (GMP grade) were supplied by Ontores
`Biotechnologies (China) and ABX (Germany), with certi-
`fied chemical purities of [ 98%. Sodium acetate, ascorbic
`acid, and mannitol were purchased as pharmaceutical-
`grade reagents from Sigma-Aldrich (USA).
`Freeze-dried kits were preformulated by using different
`amounts of DOTA-Tyr3-octreotide and DOTA-iPSMA
`peptides (ng/MBq), to evaluate the effect of the variations
`on the 177Lu-peptide radiochemical purity. The amount of
`each component in the formulation was designed for the
`
`J Radioanal Nucl Chem
`
`labeling of one lyophilized vial with 40 GBq of 177LuCl3,
`applying a factorial experimental design (Table 1). The
`analysis of variance (ANOVA) was performed with the
`GraphPad Prism software.
`
`Manufacturing process of freeze-dried kits (3
`validation runs)
`
`Preparation of the lyophilized formulations was done in
`aseptic conditions under GMPs. DOTA-iPSMA (12 mg) or
`DOTA-Tyr3-octreotide (16 mg) were dissolved in 20 mL
`of injectable-grade water (stirring and incubation at 70 °C).
`Posteriorly, 1 g of mannitol and 2 g of ascorbic acid were
`also dissolved, with stirring, in 20 mL of injectable-grade
`water. The peptide and mannitol/ascorbic acid solutions
`were then mixed (pH = 2.5–3.5). Finally, the formulation
`was sterilized by filtration (Millipore, 0.22 lm) and 2 mL
`were dosed in 20 previously-depyrogenized ampoule vials
`to then be lyophilized for 19 h (freezing at -40 °C/1 h,
`primary drying for 6 h and secondary drying at 0 °C/4 h,
`25 °C/4 h and 29 °C/4 h). After freeze-drying the formu-
`lation, the kit was stored at 2–8 °C.
`Additionally, 30 mL of 1 M sodium acetate buffer
`solution pH 5.0 was prepared, which was filtered through a
`0.22 lm membrane, and 1.5 mL were dosed in 20 sterile
`ampoule vials.
`For each one of the precursors, a manufacturing process
`validation was done, which consisted in the fabrication of
`three consecutive batches with a batch size of 20 vials
`each. The same manufacturing conditions were maintained
`to guarantee reproducibility. Process controls were estab-
`lished, such as solution pH, determination of dose volume
`through weight (n = 3), filter integrity (bubble point test,
`Millipore, BP [ 56 psi), as well as the environmental
`monitoring of viable and non-viable particles for ISO-5 and
`ISO-6 areas, in accordance with the guidelines established
`by the official Mexican regulation (NOM-241-SSA1-
`2012).
`
`Quality control and stability tests of freeze-dried kits
`
`For the quality control of the lyophilized formulations,
`parameters
`such as color, appearance, pH,
`sterility,
`
`Table 1 Factorial experimental design applied in the development of the freeze-dried kit formulations
`
`Variable
`
`Levels
`
`Values
`
`Amount of ascorbic acid (mg)
`Volume of acetate buffer (pH 5.0, 0.2 M) plus 177LuCl3 added for lyophilized powder reconstitution (mL)
`Time (h), stability
`
`3
`
`3
`
`1
`
`50, 100, 150
`
`2.0, 2.5, 3.0
`
`72
`
`Dependent variable Radiochemical purity
`
`123
`
`Evergeen Ex. 1025
`2 of 8
`
`

`

`J Radioanal Nucl Chem
`
`bacterial endotoxins and radiochemical purity (reversed
`phase HPLC, with a 3.9 mm 9 30 cm lBondapakTM C18
`column, using a gradient system), were evaluated in
`accordance with the Mexican Pharmacopeia [13], in its
`section referring to ‘‘General Methods of Analysis’’
`(MGA). The retention time of the radiolabeled peptide
`(177Lu-DOTA-Tyr3-octreotide or
`177Lu-DOTA-iPSMA)
`was 15.0 ± 2.0 min, while the retention time of 177LuCl3
`was 3.0 ± 1.0 min. All batches were subjected to stability
`tests for 12 months after their manufacturing dates.
`
`Production process: Radiochemical synthesis
`
`177Lu-DOTA-iPSMA and 177Lu-DOTA-TOC were pre-
`pared in a shielded cell (Comecer, Italy) which has a main
`compartment, waste compartment, and material entry/exit
`compartments. All compartments contain shielding made
`up of lead ingots (98% purity, with 2% Sb). The main
`chamber was equipped with a dose calibrator operated
`through specialized software and controlled through a
`touchscreen. It is also equipped with a UV lamp and a
`laminar flow system with HEPA terminal filters (99.997%
`efficiency), which was programmed with a vertical laminar
`flow of 0.3 m/s, granting an ISO Class 5 degree of clean-
`liness. For the incubation step, a Cole Palmer dry bath was
`placed within the shielded cell.
`For the radiochemical synthesis, the 177LuCl3 original
`vial (40 GBq/mL) was vented with a needle, and then
`1.0–1.5 mL of the 1 M acetate buffer pH 5.0 was added.
`The total volume was withdrawn using a sterile syringe and
`was afterward employed for the reconstitution of the
`DOTA-iPSMA or DOTA-Tyr3-octreotide lyophilized kit.
`The reconstituted vial was heated in the dry bath at 95 °C
`for 30 min. After cooling to room temperature, the vial was
`vented with a needle, and the volume was taken up to
`10 mL with injectable-grade water (Pisa, Mexico) through
`using a sterile syringe. The dosing step was carried out
`
`Fig. 1 Effect of the DOTA-
`Tyr3-octreotide and DOTA-
`iPSMA mass per added activity
`(MBq) on 177Lu-peptide
`radiochemical purity
`
`directly in delivery syringes using leaded glass shielding or
`using a dosing module (Timo-2, Comecer, Italy).
`
`Quality control and stability testing for finished
`radiopharmaceuticals
`
`For the quality control of the radiopharmaceuticals, a
`sample was taken for pH, sterility, bacterial endotoxins and
`radiochemical purity (reversed-phase HPLC/gradient sys-
`tem) tests in accordance with the Mexican Pharmacopeia
`[13], in its section referring to MGAs [13]. Stability of the
`radiolabeled products was evaluated at 72 h post-produc-
`tion by reversed-phase HPLC.
`
`In vivo studies
`
`LNCaP (PSMA-positive) human prostate cancer cells and
`AR42 J (somatostatin receptor-positive)
`rat pancreatic
`cancer cells were acquired from the ATCC (USA).
`Biodistribution and tumor uptake studies in mice were
`carried out
`in agreement with the Mexican regulation
`(NOM-062-ZOO-1999).
`LNCaP or AR42 J tumors were induced using a sub-
`cutaneous injection of cancer cells suspended in 0.1 mL
`phosphate-buffered saline (1 9 106 cells), into the upper
`back region of 8-week-old nude mice. 177Lu-octreotide or
`177Lu-iPSMA obtained from lyophilized kits (3.7 MBq in
`0.05 mL) was injected into the tail vein of the mice. The
`mice (n = 5) were sacrificed at 1, 4, 48 and 96 h post-
`injection. Tumor, lung, liver, spleen, kidney, intestine and
`blood were dissected. The activity was determined in a
`NaI(Tl) detector, along with 0.5 mL aliquots of the diluted
`standard representing 100% of the injected activity. The
`activities were used to determine the percentage of injected
`dose per gram of tissue (% ID/g).
`
`123
`
`Evergeen Ex. 1025
`3 of 8
`
`

`

`Results and discussion
`
`Freeze-dried formulation design
`
`As shown in Fig. 1, the mass per MBq necessary to obtain
`(RP) of [ 98% was different
`radiochemical purities
`between peptides, but the number of DOTA moles required
`to achieve RP over 98% was the same in both peptides
`
`Fig. 2 ANOVA results. Volume of acetate buffer (pH 5.0, 1.0 M)
`plus 177LuCl3 added for lyophilized powder reconstitution: a 2.0,
`b 2.5 and c 3.0 mL d stability at 72 h after radiochemical synthesis
`
`J Radioanal Nucl Chem
`
`(* 0.015 nmol/MBq). Therefore, differences between the
`spatial conformation of peptides with different steric hin-
`drance are not factors which affect
`the radiochemical
`reaction yield, contrary to what occurs with other peptides
`[14]. These results correlate to those reported by Iori et al.
`[6], where amounts from 11 to 40 ng/MBq were found
`suitable to obtain RP over 98% for 177Lu-peptides. Based
`on the pre-formulation study (Fig. 1), the selected amount
`of peptide per vial to obtain 37–40 GBq of 177Lu-Tyr3-
`octreotide and 177Lu-iPSMA was 0.8 mg (571 nmol) and
`0.6 mg (597 nmol), respectively.
`The ANOVA results indicated that all components have
`a significant effect (p \ 0.01) on the RP and present sig-
`(p \ 0.01)
`nificant
`interaction
`amongst
`themselves
`(Fig. 2). When 1.0–1.5 mL of the acetate buffer was added
`to the 177LuCl3 vial (1 mL) for reconstitution of the lyo-
`philized powder (total volume of 2.0 or 2.5 mL), the RP
`was over 98% at all levels of ascorbic acid mass, but after
`72 h an amount of 50 mg of ascorbic acid was not enough
`to maintain the RP over 95%, which presented the same
`behavior when a reconstitution volume of 3 mL was used.
`Therefore, the selected kit composition was: (1) one lyo-
`philized vial containing 0.8 mg (DOTA-Tyr3-octreotide) or
`0.6 mg (DOTA-iPSMA) of the peptide, 100 mg of ascorbic
`acid and 50 mg of mannitol as a diluent, and (2) a second
`vial containing 1.5 mL of 1.0 M acetate buffer pH 5.0.
`
`Table 2 Production process controls and environmental monitoring for the lyophilized peptide formulations
`
`Parameters
`
`Specification
`
`Average of three production batches
`
`pH of the final mixture
`
`Acetate buffer (pH)
`
`Volume (determined by weight) (g)
`
`Acetate buffer volume (determined by weight) (g)
`
`Filter integrity (bubble point test)
`
`Environmental monitoring
`
`ISO-5
`
`Viable particles (CFU)
`
`Total particles/m3
`
`ISO-6
`
`Viable particles (CFU)
`
`Total particles/m3
`
`123
`
`2.5–3.5
`
`4.5–5.0
`
`2.0
`
`1.5
`[ 56 psi
`
`DOTA-iPSMA
`
`DOTA-Try3-octreotide
`
`2.59
`
`4.97
`
`2.003–2.010
`
`1.502–1.511
`79.25 ± 0.33
`
`2.67
`
`4.97
`
`1.996–2.004
`
`1.500–1.510
`79.19 ± 0.19
`
`Sedimentation B 1 m3
`Contact B 1 per plate
`Air B 5 per plate
`0.5 lm B 3520
`5.0 lm B 29
`
`Sedimentation B 10 m3
`Contact B 5 per plate
`Air B 5 per plate
`0.5 lm B 35200
`5.0 lm B 293
`
`0
`
`0
`
`0
`
`0
`
`0
`
`0
`
`2
`
`3
`
`526
`
`23
`
`0
`
`0
`
`0
`
`0
`
`0
`
`1
`
`2
`
`1
`
`752
`
`15
`
`Evergeen Ex. 1025
`4 of 8
`
`

`

`J Radioanal Nucl Chem
`
`Manufacturing process
`
`The results of all three lyophilized batches for DOTA-
`iPSMA and DOTA-Tyr3-octreotide production confirmed
`that control processes and environmental conditions com-
`plied with the specifications established by the regulatory
`authorities (GMP-grade formulations) (Table 2). Thus, the
`quality control tests performed to all three validation bat-
`ches were also compliant with the specifications estab-
`lished in the Mexican Pharmacopeia as preparations
`
`suitable for human use. In general, limpid, colorless and
`sterile solutions were obtained after reconstitution, with
`bacterial endotoxins of \ 20 EU/V, pH 5.0 and average
`radiochemical purities over 97% (Fig. 3) [13].
`As can be seen in Fig. 4, DOTA-iPSMA and DOTA-
`Tyr3-octreotide lyophilized formulations were stable, since
`the three validation batches consistently produced 177Lu-
`radiopharmaceuticals with
`radiochemical
`purities
`in
`agreement with the established specification ([ 97%) [13]
`over a period of 12 months after preparation.
`
`Fig. 3 Reversed-phase radio-
`HPLC chromatograms of
`a 177Lu-iPSMA and b 177Lu-
`Tyr3-octreotide
`radiopharmaceuticals
`
`Fig. 4 Stability of three
`validation batches (01-, 02- and
`03-VAL) of a DOTA-iPSMA
`and b DOTA-Tyr3-octreotide
`lyophilized formulations over a
`12-month period, as determined
`by radiochemical purity after
`177Lu labeling
`
`123
`
`Evergeen Ex. 1025
`5 of 8
`
`

`

`J Radioanal Nucl Chem
`
`Fig. 5 Stability of a 177Lu-Tyr3-octreotide and b 177Lu-iPSMA, and c sterility and level of bacterial endotoxin at 72 h post-production
`
`Table 3 Biodistribution in mice with induced tumors after i.v. administration of 177Lu–Tyr3-octreotide or 177Lu-iPSMA prepared from lyo-
`philized kits (% ID/g)(n = 3)
`
`TISSUE
`
`177Lu-Tyr3-octreotide (AR42 J-induced tumors)
`
`177Lu-iPSMA (LNCaP-induced tumors)
`
`1 h
`
`4 h
`
`48 h
`
`96 h
`
`1 h
`
`4 h
`
`48 h
`
`96 h
`
`Blood
`
`Lung
`
`Liver
`
`Spleen
`
`Kidneys
`
`Intestine
`
`Tumor
`
`1.64 ± 0.07
`2.60 ± 0.19
`9.16 ± 0.80
`8.48 ± 0.65
`21.47 ± 1.96
`4.16 ± 1.24
`12.20 ± 1.19
`
`0.47 ± 0.02
`1.40 ± 0.08
`7.47 ± 0.40
`4.39 ± 1.14
`15.95 ± 1.28
`5.72 ± 0.29
`9.66 ± 0.92
`
`0.01 ± 0.03
`0.12 ± 0.06
`1.92 ± 0.42
`0.98 ± 0.27
`3.26 ± 0.22
`0.93 ± 0.33
`4.39 ± 1.02
`
`0.00 ± 0.00
`0.00 ± 0.00
`0.19 ± 0.07
`0.26 ± 0.08
`0.83 ± 0.42
`0.03 ± 0.02
`3.26 ± 0.62
`
`1.07 ± 0.02
`1.45 ± 0.09
`5.58 ± 0.56
`2.09 ± 0.17
`19.20 ± 1.78
`3.16 ± 0.09
`9.03 ± 1.98
`
`0.25 ± 0.03
`0.74 ± 0.04
`3.40 ± 0.31
`1.38 ± 0.24
`11.92 ± 1.01
`3.04 ± 0.16
`8.93 ± 0.84
`
`0.00 ± 0.00
`0.01 ± 0.00
`0.27 ± 0.06
`0.11 ± 0.04
`0.88 ± 0.04
`0.38 ± 0.13
`5.59 ± 1.07
`
`0.00 ± 0.00
`0.00 ± 0.00
`0.08 ± 0.02
`0.00 ± 0.00
`0.15 ± 0.09
`0.04 ± 0.03
`3.42 ± 0.74
`
`Radiochemical synthesis
`
`A total of 51 radiochemical syntheses (51 batches) were
`performed by using one lyophilized vial for each batch.
`Thirty-seven corresponded to 177Lu-Tyr3-octreotide and
`
`fourteen to 177Lu-iPSMA. The radiochemical yield in all
`cases ranged from 94.0 to 97.0% (to obtain 37.5–38.8 GBq
`of the 177Lu-peptide), with the main loss of activity in the
`177LuCl3 original vial. This yield is higher than those
`previously reported (from 70 to 90%),
`in which
`
`123
`
`Evergeen Ex. 1025
`6 of 8
`
`

`

`J Radioanal Nucl Chem
`
`radiochemical synthesizers were used [6–8]. The radio-
`chemical purity for all batches was 98.7–100% and
`remained stable after 72 h (Fig. 5). This radiochemical
`purity was slightly higher than the mean value reported by
`Iori et al. [6]. Although the general formulation was
`designed for the preparation of 37.5–38.8 GBq 177Lu-
`peptides, some batches with 20–37 GBq were also suc-
`cessfully prepared with radiochemical purities of 100% by
`177LuCl3
`using
`0.5–1.0 mL of
`(40 GBq/mL)
`plus
`1–1.5 mL of 1 M acetate buffer pH 5.0 for reconstitution
`of the lyophilized powder. From each batch, it was possible
`to obtain from 5 (7.4 GBq, 5.55 GBq or 3.7 GBq) to
`10 (3.7 GBq) doses, suitable for patients. Quality control
`tests also confirmed that no post-production sterilization is
`required since the 177Lu–iPSMA and 177Lu-Tyr3-octreotide
`radiopharmaceutical solutions maintained their sterility and
`level of bacterial endotoxin after the radiosynthesis pro-
`cedure (Fig. 5).
`Maus et al. [7] evaluated the effect of final volumes (5,
`20 and 100 mL) on the quenching effect of ascorbic acid.
`They found that at 5 mL final volume, re-addition of
`ascorbic acid with a concentration of 100 mM after
`purification resulted in radiochemical purity C 95% at
`72 h post-labeling, whereas no re-addition of ascorbic acid
`resulted in a radiochemical purity of 92% at 72 h post-
`labeling. In the case of this study, no such re-addition was
`necessary, since purification after radiolabeling was not
`necessary and the removal of ascorbic acid does not occur.
`It is also worth noting that in the formulations reported in
`this study, a concentration of 57 mM ascorbic acid was
`used, and was still capable of producing a sufficient sta-
`bilizing effect.
`It is important to note that the multi-dose kits for the
`preparation of 177Lu-iPSMA and 177Lu-octreotide, here
`developed, are limited to the exclusive use of non-carrier
`added 177Lu (40 GBq/mL, GMP-grade), with the finality of
`preparing 5 (5 doses of 7.4 GBq) or 10 (10 doses of
`3.7 GBq) doses of radiopeptide with clinical usefulness
`from only one vial.
`In Table 3, results of the biodistribution and biokinetic
`studies are shown. Establishing whether 177Lu-Tyr3-oc-
`treotide prepared from the multi-dose kit has a different
`biodistribution pattern concerning that previously reported
`for other somatostatin analog radiopeptides such as 177Lu-
`DOTA-TATE is difficult, since studies were not carried out
`under the same experimental conditions. However, one
`piece of data that may be valuable for comparison under
`different experimental conditions is the tumor-to-organ
`ratio, rather than the absolute value of % ID/g in the tumor.
`In this study, the average tumor-to-blood ratio was 20.6 at
`4 h for 177Lu-Tyr3-octreotide, which is in agreement with
`previously reported preclinical results for 177Lu-DOTA-
`TATE [15].
`
`Conclusions
`
`The production of radiochemical precursors (177LuCl3) and
`lyophilized ligand formulations as sterilized and GMP-
`grade products, allows fast and routine preparation of 177Lu
`therapeutic radiopharmaceuticals with a quality suitable for
`clinical use. This procedure lacks the need for the use of an
`automated synthesizer and thus reduces production costs.
`
`Acknowledgements This research was carried out as part of the
`activities of the ‘‘Laboratorio Nacional de Investigacio´n y Desarrollo
`de Radiofa´rmacos,
`(Mexican National Council of Science and
`Technology, CONACyT)’’.
`
`References
`
`1. Banerjee S, Pillai M, Knapp F (2015) 177Lu therapeutic radio-
`pharmaceuticals: linking chemistry, radiochemistry, and practical
`applications. Chem Rev 115(8):2934–2974
`2. Ferro-Flores G, Ocampo-Garcı´a BE, Santos-Cuevas CL, de Maria
`Ramirez F, Azorin-Vega EP, Mele´ndez-Alafort L (2015) Thera-
`nostic radiopharmaceuticals based on gold nanoparticles labeled
`with 177Lu and conjugated to peptides. Curr Radiopharm
`8(2):150–159
`3. Kim S-J, Pak K, Koo PJ, Kwak JJ, Chang S (2015) The efficacy
`177Lu-labelled peptide receptor
`of
`radionuclide therapy in
`patients with neuroendocrine tumours: a meta-analysis. Eur J
`Nucl Med Mol Imaging 42(13):1964–1970
`4. Baum RP, Kluge AW, Kulkarni H, Schorr-Neufing U, Niepsch K,
`Bitterlich N, van Echteld CJ (2016) [177Lu-DOTA] 0-D-Phe1-
`Tyr3-octreotide (177Lu-DOTATOC) for peptide receptor radio-
`therapy in patients with advanced neuroendocrine tumours: a
`phase-II study. Theranostics 6(4):501
`5. Rahbar K, Ahmadzadehfar H, Kratochwil C, Haberkorn U,
`Scha¨fers M, Essler M, Baum RP, Kulkarni HR, Schmidt M,
`Drzezga A (2017) German multicenter study investigating 177Lu-
`PSMA-617 radioligand therapy in advanced prostate cancer
`patients. J Nucl Med 58(1):85–90
`6. Iori M, Capponi PC, Rubagotti S, Esposizione LR, Seemann J,
`Pitzschler R, Dreger T, Formisano D, Grassi E, Fioroni F (2017)
`Labelling of Y-and Lu-DOTA-bioconjugates
`for
`targeted
`radionuclide therapy: a comparison among manual, semiauto-
`mated, and fully automated synthesis. Contrast Media Mol
`Imaging. https://doi.org/10.1155/2017/8160134
`7. Maus S, de Blois E, Ament SJ, Schreckenberger M, Breeman WA
`(2014) Aspects on radiolabeling of 177Lu-DOTA-TATE: after
`C18 purification re-addition of ascorbic acid is required to
`maintain radiochemical purity. Int J Diag Imaging 1(1):5
`8. Kroselj M, Socan A, Zaletel K, Dreger T, Knopp R, Gmeiner T,
`Kolenc Peitl P (2016) A novel, self-shielded modular radiosyn-
`thesis system for fully automated preparation of PET and thera-
`peutic radiopharmaceuticals. Nucl Med Commun 37(2):207–214
`9. Das T, Banerjee S, Shinto A, Kamaleshwaran K, Sarma H (2014)
`Preparation of Therapeutic Dose of 177Lu-DOTA-TATE using a
`novel single vial freeze-dried kit: a comparison with in situ.
`Preparation at hospital
`radiopharmacy. Curr Radiopharm
`7(1):12–19
`10. Kunikowska J, Krolicki L, Hubalewska-Dydejcyk A, Mikola-
`jczak R, Sowa-Staszczak A, Pawlak D (2011) Clinical results of
`radionuclide therapy of neuroendocrine tumours with 90Y-
`DOTATATE and tamdem 90Y/177Lu-DOTATATE: which is a
`
`123
`
`Evergeen Ex. 1025
`7 of 8
`
`

`

`Imaging
`
`J Nucl Med Mol
`
`therapy option? Eur
`better
`38(10):1788–1797
`11. Das T, Bhadwal M, Banerjee S, Sarma HD, Shinto A,
`Kamaleshwaran KK (2014) Preparation of DOTA-TATE and
`DOTA-NOC freeze-dried kits for formulation of patient doses of
`177Lu-labeled agents and their comparison for peptide receptor
`radionuclide therapy application.
`J Radioanal Nucl Chem
`299(3):1389–1398
`12. Kwekkeboom D, Bakker W, Kooij P, Konijnenberg M, Srini-
`vasan A, Erion J, Schmidt M, Bugaj J, Jong M, Krenning E
`(2001) [177Lu-DOTA0, Tyr3]octreotate: comparison with [111In-
`DTPA0] octreotide in patients. Eur J Nucl Med 28(9):1319–1325
`
`J Radioanal Nucl Chem
`
`13. Farmacopea de los Estados Unidos Mexicanos (2014). 11 edn.
`Secretaria de salud, Mexico City
`14. Ferro-Flores G, de Ramirez FM, Melendez-Alafort L, de Murphy
`CA, Pedraza-Lopez M (2004) Molecular recognition and stability
`of 99mTc-UBI 29-41 based on experimental and semiempirical
`results. Appl Radiat Isot 61(6):1261–1268
`15. Rodrı´guez-Corte´s J, Arteaga de Murphy C, Ferro-Flores G,
`Pedraza-Lo´pez M, Murphy-Stack E (2007) Biokinetics and
`dosimetry with 177Lu-DOTA-TATE in athymic mice. Radiat Eff
`Defects Solids 162(10–11):791–796
`
`123
`
`Evergeen Ex. 1025
`8 of 8
`
`